I originally played through XCOM: EU on PS3 (on PS Plus). I completed the game but I've just purchased the Steam version because a) I wish to support the devs for an amazing game and b) I think it will play much better on PC (with no PS3 controller bugs!).

I've installed XCOM: EU on my machine but I have still yet to play Slingshot or Enemy Within.

Does anyone know if Enemy Within is a totally new game? (with no use of previous levels) or would it work with the original levels and Slingshot levels?

I would hate to miss the Slingshot add-on once I installed Enemy Within. Of course, playing through 3 times is an option (2nd for Slingshot and 3rd for Enemy Within) but it would be cool if I could experience everything in my 2nd play through LOL

As far as I know, you can enable Slingshot within Enemy Within - but I think, then you can't play Prodegy (according to one Interview. If that DLC is triggered by another mission than the first Council, then both should work)

As far as I know, you can enable Slingshot within Enemy Within - but I think, then you can't play Prodegy (according to one Interview. If that DLC is triggered by another mission than the first Council, then both should work)

Really don't see where this impression is coming from, considering the only article which even mentions Progeny is this one: